Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With destructiveHint=true and readOnlyHint=false already declared, the description adds the key clarification "No Meta write" — the discard only affects the local prepared change and does not propagate to the platform. That is meaningful context beyond the annotations, though it says nothing about invalid/expired token behavior or whether the token is single-use.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three short sentences with zero filler: action and required token first, the safety clarification second, sibling routing last. Nothing is repeated from the annotations or title and no sentence is wasted.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

An output schema exists, so return-value explanation is not needed, and the annotations cover the destructive/read-only profile. Purpose, required token form, and alternative tools are all present; only edge-case behavior (invalid token, whether the prepared update can be recovered after denial) is absent.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, so the description must carry parameter meaning. It does add real value for confirm_token by disclosing the accepted prefixes (bu_confirm_*, mu_confirm_*) and stressing the token must be exact, but connection_context is entirely undocumented in both schema and description, so compensation is only partial.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb ("Discard") and a specific resource (a prepared status, campaign/ad-set budget or bid update), plus the exact token types it consumes. It is immediately distinguishable from siblings like overview_update_confirm and the various *_prepare_* tools because it names the discard action explicitly.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly routes the agent away from this tool: "Use launch_deny for creation/copy drafts and products_delivery_pause_deny for product-family pauses." That names both alternatives and the condition that selects each, which is exactly the when/when-not guidance an agent needs.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.